Systems that allow for on-site, precision cutting of granite, marble, and other stone-type materials, such as for building cladding, countertops and stairways, are very desirable, in part because they help eliminate the inefficiency and potential inaccuracy that can be introduced into a job when stone cuts must be done with large specialized equipment, typically in a stone factory or workshop. It has proven desirable to have a track saw system in which the tracks rest directly on the stone being cut, thus taking advantage of the natural rigidity of the stone and characteristic flatness of stone slabs being used for counter tops and similar jobs, to omit the unnecessary and often extreme extra weight and bulk of additional equipment. In particular, the AccuGlide saw system, described by the Applicant in U.S. Pat. No. 5,960,780, provides a lightweight, highly portable, and affordable system in which a stone-cutting saw, with a circular blade that is configured to be substantially perpendicular to a base of the stone-cutting saw, is guided along a set of tracks that rest on the stone workpiece.
Until now, however, a successful system has not been made available for making cuts in the workpiece at other than 90° angles at the job site. Making such angled cuts, known as mitering, beveling, or chamfering, is an important and frequently needed task for professional stoneworkers. In particular, no analogous track saw system has been developed to allow rails of a track saw system to be supported by the stone being miter cut without reliance on additional, very heavy, and non-portable equipment. Instead, most mitering of workpiece edges is currently done off-site, with on-site portions of the job being carried out using hand tools such as a hand grinder that grinds away the unwanted stone in an operation that, due in part to the inconsistent crystalline structure of natural stone, is prone to rippling and other inaccuracies. Mitering by grinding the stone with a power router as opposed to cutting the stone with a diamond saw is typically far more costly in terms of time and wear-and-tear on the equipment used, as well being more physically stressful to the stone-worker's body. In fact, it is currently estimated that for a typical kitchen countertop job, less than 25% of the labor costs involve cutting the stone, while 60–75% of the labor costs involve finishing the edges of the stone, including templating, laminating, hand-shaping, and polishing operations.
Attempts to adapt existing portable mitering saw systems and methods, such as those designed for use with wood and other softer and lighter-weight materials, have thus far not been successful for a number of reasons. For one thing, because of the far greater demands made on the blade used for stonecutting, whether for straight or angled cuts, a step-cut type of operation is preferred for cutting stone, in which a desired cut is made incrementally with a series of successively deeper cuts in the stone, for example, at ¼″ deeper per pass. This step-cut method makes accurate repeatability of the angle of a cut much more crucial for stonework than for woodwork, especially if the final angled edge is to be smooth and ridge-free. Due in part to this higher demand for angle repeatability, tilting the motor and blade of the saw with respect to the base of the saw, as can be done with the less-rigid SKIL™ saw designs used for wood cutting, does not work well for stone-cutting saws.
Although traditional tooling with very large, heavy, non-portable, and expensive pieces of machinery, such as a gantry saw, bridge saw, or computer numeric control (CNC) saw, may provide for cleanly mitered cuts in stone slabs, such systems may typically cost up to hundreds of thousands of dollars each, and, at 12–14 feet long, do not provide the portability so desired by stoneworkers for on-site jobs.